Fuse



April 12, 1949.

C. F. NELSON FUSE Filed Sept. 22, 1943 gmm'p EARLENELSDN,

Patented Apr. l2, 1949 @.CarllF.; 'Nelson, Wharton, N,i.I.;assignon.,to...the :United .StatesyofAmerica `as vreln'esenicd byljthe"Secretary of War eApplicatiomSeptemher '22, 193-.Seri al No: 50354-12(Clif IGZ-L20) Z Claims.

' "This 'inventionE relatesztof-affuze'ot therbarometric type forexploding shells-bombsaor roel-:ets -t a selected or predeterminedaltitude.

'I'Anobjectio thelinvention isctolprovidea fuze vwhich maybe applied'to`a rocket, 'slellon bomb whichV will' in'tiatethe explosion of` thefexplosive charge carriedbyy the rocket;.-sh'ell onfbombwhen it hasreached a selected von:predetermined@posi-- 'tionor :levlel Ainfits"flight. C'The 'fuze according` vvtothe f finvention'ldependsfor'itsactuation upon dift'erencesinatmospherlc pressure prevailingl atVarious -level's above .the surface 4of the-earth. VBeforefring ofitherocket orv "shell` carrying the l '-fuzef according: Itol' thevinfvention, or before' releasing from` aircraft aibomfb provided UwithA'the fuze, thefuze lmay-loe setwto become operative" to A'initiate theexplosion'of the explosive charge of the f lbornb, 'shell or rocket when'the latter has: reachedfa selected.y onpredetermined altitude orlei/elI in-the=- atmosphere, The manner' in= Whi'chtliey fuzefisconstructed :is illustrated inf the accompanyingdrawings-fand 'explainediny 'the yWritten descriptionigiven below which refersby'characters ofAreference -to=the `said'1drawings. In the saiddrawings:

A"Figure 1 -is ailongitudinalfsectiomthrouglrthe longitudinal axisof'the fuze;

Figure 2 is a cross section on the line 2.-`2l--of Fgurei 1;

'-'Figure-Si is anffenlargedasection of. part fofvthe rack shown inligurei l; with aI 1part of.I .the-operating means or rod therefor shownin elevation; Figure 4 -isschematic representation, partly inperspective, illustrating the electric circuit used in the fuze and howitfoperates to cause the explosion of the ,'explosiva v`charge carriedbytthe rocket, shell or bomb at the selectedgorpredeter mined level;

Figure 5 is' a--perspeetive'view ofn the U-shaped springfshown inelevation fin Figure 1; and

-1 Figure (iis an elevation otsthe-xneans;byv which one: offthelegs ofthe springis,engagedwitlrthe aneroid means shown infFigure l.:Referring-mow specicallyatothe accompanying drawingain ,which the.same..,characters of reference in the several views indicate the sameparu-,the numeral I indicatesthe body portion-mf' the rocken.. shell orbomb'` whichfcarries. thetxexplosive charge 2.

The base portion of the fuze comprises a cir- Y cular member or adapter3 which is attached by iii) '2 screw threads to the -body portion 4 ofthefuze andsbyfscrew threads -to vthe body portion I-of the rocket;shellior bomb. -The rmember oradapter# 3 is formed with a cavity 5 of asuitable sizeto accommodate electric: condenser 6 Vand'electric .primer'1. Electric -cond'enser 6 and electric primerf 'l may be :securedincavityI 5 by any 5suitable lholding means! attached to adapterL 3. Inthedrawingsy such holding means are illustrated Condenser: 6 serves asa-source-of electrical energykfor -producingfa sparky between theterminals Il and I2 of the spark gap I4 in thevelec'- tric primerf'l'.tfWliile acondenser is shown as vthe source of lelectrica-'er-iergy, `itis tov-be -understood that: any other suitable-source of electricalenergy torifthe` electric-'primer maybe employed. AFor example, asmall`-iriduction coilv or Ruhmkori coil` and small idry cells" may beused toy produce the difference of potential necessary to cause sparksacross spark gap AI ily -of' the primer4 l. Whenf'f a ycondenseri'sfemployed liti is" chargedJ 'in any1 suitablet manner-shortly*beforeA the* fuzeV is put to=use-.

*2Dhe1adapter1 3f isfvprovided with a plate' lli-of electricalinsulation KNmaterial y--Whiclfl is `sunk therein and secured'thereto;vont-the7 upper side thereof.v Secured to thisplate is abracket iI6having-a base#portiony H and-:1anoverhanging head po'rtion'il'll.#Pla-te I5-serves -to'insulate the bracket I`8"from:1the adapter 3.

Mounted on; -the -base vI Lofi-bracket i6 is-a pair fffguides2l)`v andEl :for the: rack 22, ywhich hold theack uporrbase 11i-while permittingit to slide longitudinally.

'Headportion l8-of then-bracket |6 and base portioni'l 1- of- 'saldiy-bracket areA respectively provide'diwith bearings 22 f1 andi 23 ofinsulating material1 lfr ni'tlieshaft24. FiXedt'o theY shaft 24 isa-jgpinior1-Y ZSZffWhich-z-,meshes'with rack 22.. 'Shaft2,j.at"its`.1ower end, extends into .an opening. 2'6 in adapter 3', intoWhich opening projects a Spring electrical. connection for.. connectingthe. lower cndl..of..l7hef.sl1aft..24. Witli .nne side, Aor with one ,terminal.of'` ,the .eondenser- 6-athe ,other lterminal ofatheucondensernbeing 4connected by :means of the-nsulated ccnductorZBvtofthe. terminal l 2 vof the ele ctric:'r-primaer ,f'lfhe Iterrninal"iAH fof-the .ecilllmr fis rfgroundedtothe `aiiapterfS which in turniseroundeatofbodw 4.

SiShaft 245e ati dis-: upperf;end;A passes; .througlr .in-

fixed to its upper end by a pin or set screw 3|. The purpose of this armis to close the electric circuit which includes the condenser 6 and theresponsive to variations in atmospheric pressure,v

is indicated by the numeral 35. This capsule` is ysecured* by brazing orsoldering to the head 36 of a bolt 31. The bolt 31 passes through anopening 38 (see Fig. 5) in U-spring 39 and through an opening in thevertical portion of bracket |`6. Upon tightening the nut 49 on bolt 31the spring 39 is clamped between the head 36 of the bolt 31 and thewasher 42, and the pressure responsive member assumes the position shownin Figure 1.

The pressure responsive member or capsule 35,

on the side opposite the side to which thebolt is attached, carriesengaging means for the unsecured end of spring 39. Engaging means 45 maybe soldered or brazed or otherwise suitably attached to the pressureresponsive means 35. Engaging means 45 (see Fig. 6) is provided with ahead portion 46 and a circular groove 45a adiacent thereto in order toprovide a neck portion 45h.

Spring 39 (see Fig. 5) is provided with a slot 41 within which the neck45D (see Fig. 6) of the spring engaging means 45 fitswith a sliding t.

The shoulders provided by the groove 45am eny gaging means 45 engageover the ngers48 and 49 adjacent the slot 41, whereby the engaging means45 and spring 39 may move outwardly together with a sliding t of thefingers 48 and 49 in the groove 45a.

To the finger 48 of spring 39 is attached a rod 59 which extends fromsaid nger into an openving 5| v(see Fig. f3) in the body ofthe rack 22.

The rod 59 fits slidingly in the opening 5| so as to permit the rack 22to be moved by it longitudinally between the guides 29 rand 2| (seeiFig. 2).

A nose 55 is tted into and carried by the fuze body 4, and is heldthereon by friction ring 56 and set screws pressing upon said frictionring, one of said set screws being indicated by the numeral 51 inFigure 1. Nose 55 may be rotated l relative to body portion 4 and isheld in the position to which it is rotated by the action .of frictionring 56.

The nose portion is hollow as shown, and carries on its interior, nearits bottom, a projection 58 (see Fig. 2) which lies in the path of themotion of the outer end of the arm 39.V

From the foregoing it will be appreciated that the nose 55 may berotated to position the projection 58 at any desired position relativeto the initial or zero position of the arm 30. Graduations 59 areprovided upon the nose 55, which in conjunction with the index 60 on thebody portion 4, enables the position of projection 58 with respect toarm 39 to be set as desired. The graduations 59 represent altitudes atwhich the fuze will set off the explosive charge in the rocket, shellorbomb. f

In order to maintain the air pressure Within the fuze body and nose thesame as the pressure of the air or atmospheric level through which thefuze passes in night, the openings 65 in the nose 55 and openings 66 inthe body 4 are provided. Openings 65 and 66 are so proportioned that theamount of air entering holes 65 is the same as the amount leaving fromholes 66.

Operation: Nose 55 is rotated until the graduations 59 and index 69indicate the altitude or 4 atmospheric level at which it is intendedthat the explosive charge 2 shall be exploded. For the purposes ofexplanation, it is assumed that the fuze has been applied to a rocket,and that the condenser 6 has beencharged. As the rocket ascends, thepressure responsive capsule or means 35expands. This expansion increasesthe distance between the legs of the U-spring 39,

whereby the rod 59, as shown in Fig. l, moves to the right.v Themovement of rod 59 is communicated to rack 22, which, being inengagement with pinion 25, causes the rotation of the latter and ofshaft 24 and arm 39. When the rocket has reached the altitude or levelfor which the fuze has been set for exploding the charge 2, theouter/end of the arm 39 makes contact with the projection or contact 58,thereby closing the circuit (see Fig. 4) including the condenser 6. andprimer 1. When this circuit is closed, sparks pass across the spark gap|4 of the primer 1 and these sparks fire the primer. The primer uponbeing red sets 'on they explosion of the explosive charge 2.

I claim:

1. In a fuze of theL type described adapted for use with a projectile, ahollow body, an adapter constructed and arranged to secure said body insaid projectile, the said adapter being provided with a cavity openinginto said projectile, an electric primer in said cavity, a source ofelectrical energy operatively connected with said primer, barometriomeans responsive'to variation in air pressure in said body, a U-shapedspring in said body, the said spring having one leg xed and the otherleg inengagement with said barometric means and responsive todifferences in atmospheric pressure, a rack, means for communicating themotion of said last mentioned leg to said rack, a shaft, a pinionmounted on said shaft and meshing with said rack, whereby the said shaftis rotated upon movement of said rack, an arm fixed on said shaft forrotation therewith, a nose rotatably mounted on said body, acircumferential gauge on said nose calibrated with the pressure responseof said barometric means, an electrical contact on said nose in the pathof motion of said arm responsive to rota tion of said nose to bepositioned in a predetermined position relative to said arm and anelectrical circuit including said arm, said contact. said electricprimer, and said source of electric energy.

2. The structure of claim 1 in which insulating means are providedbetween the cavity in the adapter and the body of the fuze.

CARL F. NELSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,283,075 Chacon Oct. 29, 19181,351,130v Roesch Aug. 31, 1929 1,841,983 Ruhlemann Jan. 19, 19322,167,412 Baesecke July 25, 1939 FOREIGN PATENTS l Number Country Date166,562 Great Britain 1921

